Barker is married with three children. After graduating from the University of Cincinnati College of Law and a stint in the United States Army Medical Services Corps in the late 1960s, he worked in private practice until 1983. He was then appointed to the Circuit Court for the 11th Judicial District. He was elected to the position in 1984 and again in 1990. During his trial court tenure, Barker was consistently given the highest rating for a Circuit Court judge in Chattanooga Bar Association polls.
In 1995, Gov. Don Sundquist appointed Barker to the state Court of Criminal Appeals; the following year, he was elected to an eight-year term. Barker was appointed to the Tennessee Supreme Court in 1998 and was elected to a full eight-year term the same year and again in 2006. His colleagues on the court unanimously elected him chief justice in 2005. 
Barker retired effective at noon September 1, 2008 after a judicial career spanning 25 years.
“It has been a great honor to serve the first twelve years as a circuit judge in Chattanooga, followed by three years on the Court of Criminal Appeals, and the last ten as a member of our State Supreme Court,” Barker wrote in a letter to Gov. Phil Bredesen. “It has been my highest professional honor to have been chosen by my colleagues to serve as Chief Justice these past three years.”
|Former||William Barker • Janice Holder • William Koch • Martha Daughtrey • Horace Harmon Lurton • Paul Summers •|